Lack of adequate oxygenation of brain tissue causes brain injury. A stroke occurs when the blood supply to part of the brain is suddenly interrupted or when a blood vessel in the brain bursts, spilling blood into the spaces surrounding brain cells, or when the brain or a portion of the brain is deprived of oxygen or oxygenation is impaired by exogenous substances such as carbon monoxide, hemorrhage, or hypoperfusion. Brain cells die when they no longer receive adequate oxygen and nutrients from the blood or there is sudden bleeding into or around the brain. The symptoms of a stroke include sudden numbness or weakness, especially on one side of the body; sudden confusion or trouble speaking or understanding speech; sudden trouble seeing in one or both eyes; sudden trouble with walking, dizziness, or loss of balance or coordination; or sudden severe headache with no known cause. There are several forms of stroke, including: ischemic—blockage of a blood vessel supplying the brain, due to thrombosis or embolus, and hemorrhagic—bleeding into the brain tissue (intracerebral hemorrhage), or into the subarachnoid space (subarachnoid hemorrhage). Brain injury can also occur from subdural or epidural hematoma. Stroke involving the spinal cord can also occur due to the same or similar causes of stroke involving the brain (ischemia, hemorrhage, hypoperfusion, etc.). Traumatic brain injury (TBI), a form of acquired brain injury, occurs when a sudden trauma causes damage to the brain. TBI can result when the head suddenly and violently hits an object, or when an object pierces the skull and enters brain tissue. Symptoms of a TBI can be mild, moderate, or severe, depending on the extent of the damage to the brain. A person with a mild TBI may remain conscious or may experience a loss of consciousness for a few seconds or minutes. Other symptoms of mild TBI include headache, confusion, lightheadedness, dizziness, blurred vision or tired eyes, ringing in the ears, bad taste in the mouth, fatigue or lethargy, a change in sleep patterns, behavioral or mood changes, and trouble with memory, concentration, attention, or thinking. A person with a moderate or severe TBI may show these same symptoms, but may also have a headache that gets worse or does not go away, repeated vomiting or nausea, convulsions or seizures, an inability to awaken from sleep, dilation of one or both pupils of the eyes, slurred speech, weakness or numbness in the extremities, loss of coordination, and increased confusion, restlessness, or agitation. Adverse residual neurological and brain effects from TBI occurring years before can continue. These chronic adverse effects can include difficulties with attention, concentration, planning, calculation, reading, vision, hearing, balance and motor activities such as walking or use of hands or limbs. Traumatic brain injury can occur from repeated trauma to the head, such as occurs in contact sports such as football, boxing, or soccer, or repeated concussions of any origin.
Cerebral hypoxia refers to a condition in which there is a decrease of oxygen supply to the brain even though there is adequate blood flow. Drowning, strangling, choking, suffocation, cardiac arrest, head trauma, carbon monoxide poisoning, and complications of general anesthesia can create conditions that can lead to cerebral hypoxia. Symptoms of mild cerebral hypoxia include inattentiveness, poor judgment, memory loss, and a decrease in motor coordination. Brain cells are extremely sensitive to oxygen deprivation and can begin to die within five minutes after oxygen supply has been cut off. When hypoxia lasts for longer periods of time, it can cause coma, seizures, and even brain death. Brain injury can also occur due to radiation exposure or chemotherapy.
Spasticity is a condition in which there is an abnormal increase in muscle tone or stiffness of muscle, which might interfere with movement, speech, or be associated with discomfort or pain. Spasticity is usually caused by damage to nerve pathways within the brain or spinal cord that control muscle movement. It may occur in association with spinal cord injury, multiple sclerosis, cerebral palsy, stroke, brain or head trauma, amyotrophic lateral sclerosis, hereditary spastic paraplegias, and metabolic diseases such as adrenoleukodystrophy, phenylketonuria, and Krabbe disease. Symptoms may include hypertonicity (increased muscle tone), clonus (a series of rapid muscle contractions), exaggerated deep tendon reflexes, muscle spasms, scissoring (involuntary crossing of the legs), and fixed joints (contractures). The degree of spasticity varies from mild muscle stiffness to severe, painful, and uncontrollable muscle spasms. Spasticity can interfere with rehabilitation in patients with certain disorders, and often interferes with daily activities. (From the National Institute of Neurological Disorders and Stroke Spasticity Information webpage).
The methods of the present invention are designed to treat mammals, including humans, following stroke or other forms of neurological or brain injury (BI). Causes of BI include, but are not limited to stroke, automobile accident, anesthesia accident, near-drowning, or cerebral hemorrhage. The most common causes of BI are stroke, trauma (falls, automobile accidents, or firearm accidents); birth injuries or cerebral hypoxia. BI causes widespread, unmet medical needs, producing chronic motor deficits, spasticity, sensory deficits, cognitive deficits, deficits in attention, and alterations in mood and behavior for which current medical treatment is inadequate. Cerebral palsy is caused by brain injury prior to birth, at birth, or within the first two years of life.
Following brain injury various neuropsychiatric disorders may develop, including depression, anxiety, agitation, and post-traumatic stress disorder (PTSD). PTSD symptoms include flashbacks or bad dreams, emotional numbness, intense guilt or worry, angry outbursts, feeling “on edge,” or avoiding thoughts and situations that remind them of the trauma. In PTSD, these symptoms last at least one month (National Institute of Mental Health). Traumatic events that may trigger PTSD include military combat, natural disasters, and violent crime. The methods of the present invention may be used to treat the neuropsychiatric disorders enumerated above that occur following brain injury.
Tumor necrosis factor-alpha (TNF) (the term “TNF” is equivalent to and used interchangeably herein with the term “TNF-alpha”) is an endogenous molecule that modulates neuronal communication and the immune response. TNF plays a key role in the inflammatory response, in the immune response, and in the response to infection. TNF is formed by the cleavage of a precursor transmembrane protein, forming soluble molecules which aggregate in vivo to form trimolecular complexes. These complexes then bind to receptors found on a variety of cells. Binding produces an array of pro-inflammatory effects, including release of other inflammatory molecules, including interleukin (IL)-6, IL-8, and IL-1; release of matrix metalloproteinases; and up-regulation of the expression of endothelial adhesion molecules, further amplifying the inflammatory and immune cascade by attracting leukocytes into extravascular tissues.
Interleukins are another group of molecules that modulate the immune response. Both TNF and interleukins are cytokines Cytokines are a group of endogenous signaling molecules. Therapeutic molecules that directly interfere with the biologic effects of cytokines (termed “cytokine antagonists”, or, interchangeably “cytokine inhibitors”) can be manufactured using biotechnology (e.g. recombinant DNA technology), or can be harvested from living organisms. Therapeutic molecules created by biologic processes derived from a living source are termed “biologics”, in contrast to drugs that are chemically synthesized. The living sources may include humans, other animals, or microorganisms. Biologics are regulated through a specific division of the FDA. Cytokine antagonists have been developed for therapeutic human use, including biologic TNF antagonists and interleukin antagonists that take various forms, such as monoclonal antibodies, domain antibodies, antibody fragments, and fusion proteins. “TNF antagonist” and “TNF inhibitor” are terms used herein interchangeably.
Antibodies (immunoglobulins) are proteins produced by one class of lymphocytes (B cells) in response to specific exogenous foreign molecules (antigens). Monoclonal antibodies (mAb), identical immunoglobulin copies which recognize a single antigen, are derived from clones (identical copies) of a single B cell. This technology enables large quantities of an immunoglobulin with a specific target to be mass produced.
Monoclonal antibodies with a high affinity for a specific cytokine will tend to reduce the biological activity of that cytokine Substances which reduce the biological effect of a cytokine can be described in any of the following ways: as a cytokine blocker; as a cytokine inhibitor; or as a cytokine antagonist. In this patent, the terms “blocker”, “inhibitor”, and “antagonist” are used interchangeably with respect to cytokines. Domain Antibodies (dAbs) are the smallest functional binding units of antibodies, corresponding to the variable regions of either the heavy (VH) or light (VL) chains of human antibodies, and are effective cytokine antagonists. Domain antibodies are antibody fragments. Other types of antibody fragments, such as pegylated antibody fragments (e.g. certolizumab pegol) are effective cytokine antagonists.
U.S. Pat. No. 5,385,901 entitled “Method of Treating Abnormal Concentrations of TNF Alpha” discloses a method for the use of TNF antagonists. This patent does not teach the use of a biologic delivered via the vertebral venous system, as described in the present invention, for the suppression and inhibition of the action of TNF in the human body to treat disorders of the brain. U.S. Pat. No. 5,434,170 entitled “Method For Treating Neurocognitive Disorders” discloses the use of thalidomide to treat dementia. This patent does not teach the use of etanercept or another biologic delivered via the vertebral venous system to treat disorders of the brain. U.S. Pat. No. 6,277,969 discloses the use of anti-TNF antibodies for treatment of various disorders. This patent does not teach the use of etanercept or another biologic delivered via the vertebral venous system to treat disorders of the brain. U.S. Patent application 2004/0258671 by Watkins entitled “Methods for Treating Pain” discloses the use of IL-10 and IL-10 fusion protein and other biologics for treating pain. This patient application does not disclose the use of these substances to treat disorders of the brain. U.S. Pat. No. 5,656,272 to Le et al. discloses the use of TNF inhibitors for treatment of various disorders, including the use of anti-TNF monoclonal antibodies. This patent does not teach the use of etanercept or another biologic delivered via the vertebral venous system to treat disorders of the brain. U.S. Pat. No. 5,650,396 discloses a method of treating multiple sclerosis (MS) by blocking and inhibiting the action of TNF in a patient. This patent does not teach the use of etanercept or another biologic delivered via the vertebral venous system to treat disorders of the brain. U.S. Pat. No. 5,605,690 discloses the use of TNF inhibitors for treatment of various disorders. This patent does not teach the use of etanercept or another biologic delivered via the vertebral venous system to treat disorders of the brain. U.S. published application US 2003/0148955 to Pluenneke discusses etanercept treatment for dozens of clinical disorders, but it does not discuss treatment of brain injury, perispinal administration, use of the vertebral venous system, Trendelenburg positioning, nor other aspects of the current invention. U.S. Pat. Nos. 7,115,557, 6,649,589 and 6,635,250 and related applications, to Olmarker and Rydevik, and previous publications by Olmarker (see References) discuss the use of TNF inhibitors for the treatment of nerve root injury and related disorders. These patents do not teach the use of etanercept or another biologic delivered via the vertebral venous system as described in the present invention to treat disorders of the brain, and are not enabling with respect to etanercept, certolizumab pegol, and other molecules discussed herein. U.S. Pat. No. 5,863,769 discloses using IL-1 RA for treating various diseases. This patent does not teach the use of an interleukin antagonist or other biologic delivered via the vertebral venous system to treat disorders of the brain. U.S. Pat. No. 6,013,253 discloses using interferon and IL-1 RA for treating multiple sclerosis. This patent does not teach the use of an interleukin antagonist or other biologic delivered via the vertebral venous system to treat disorders of the brain. U.S. Pat. No. 5,075,222 discloses the use of IL-1 inhibitors for treatment of various disorders. This prior art patent does not teach the use of an interleukin antagonist or other biologic delivered via the vertebral venous system to treat disorders of the brain. U.S. Pat. No. 6,159,460 discloses the use of IL-1 inhibitors for the treatment of various disorders. This prior art patent does not teach the use of an interleukin antagonist or other biologic delivered via the vertebral venous system to treat disorders of the brain. U.S. Pat. No. 6,096,728 discloses the use of IL-1 inhibitors for treatment of various disorders. This prior art patent does not teach the use of an interleukin antagonist or other biologic delivered via the vertebral venous system to treat disorders of the brain.
Clemens (Clemens H J. Die Venensysteme der menschlichen Wirbsèaule; Morphologie und funktionelle Bedeutung (De Gruyter, Berlin, 1961) demonstrated that the internal and external vertebral venous plexuses freely intercommunicate. But Clemens did not discuss the use of the vertebral venous system (VVS) to facilitate delivery of large molecules to the brain, nor did he discuss the use of the VVS for therapeutic purposes. Groen (Groen R J, Groenewegen H J, van Alphen H A, Hoogland P V. Morphology of the human internal vertebral venous plexus: a cadaver study after intravenous Araldite CY 221 injection. Anat Rec, 249(2), 285-294 (1997) confirmed the fact that all three divisions of the VVS (internal and external plexuses, and the basivertebral veins) freely intercommunicated, and that all divisions of this system lacked valves. But Groen did not discuss the use of the VVS to facilitate delivery of large molecules to the brain, nor did he discuss the use of the VVS for therapeutic purposes. Batson in 1940 (Batson O V. The Function of the Vertebral Veins and their role in the spread of metastases. Annals of Surgery, 112, 138-149) published information regarding the vertebral venous system. Experimentally he demonstrated a connection between the pelvic venous system and the vertebral venous system, and proposed that this was a route whereby carcinoma originating in the pelvis could metastasize to the spine. His work did not propose the use of the VVS for therapeutic purposes, nor did it discuss or imply this possiblity. His work did not suggest delivery of biologics to the brain. Gisolf (Gisolf J, van Lieshout J J, van Heusden K, Pott F, Stok W J, Karemaker J M. Human cerebral venous outflow pathway depends on posture and central venous pressure. J Physiol, 560(Pt 1), 317-327 (2004)) discussed the vertebral venous system and its connections to the cranial venous system, but did not discuss the potential use of this system as a route of administration of biologics to the brain. Retrograde cerebral perfusion has been previously demonstrated to deliver dye to the surface of the brain in pigs after superior vena caval injection (Ye J, Yang L, Del Bigio, et. al. Retrograde cerebral perfusion provides limited distribution of blood flow to the brain: a study in pigs. J Thorac Cardiovasc Surg. 1997 October; 114 (4):660-5) but the authors did not propose the use of this route to deliver biologics to the brain. Groen (Groen R, du Toit D, Phillips F, et. al. Anatomical and Pathological Considerations in Percutaneous Vertebroplasty and Kyphoplasty: A reappraisal of the vertebral venous system. Spine 29(13): 1465-1471 (2004)) discussed the anatomy and function of the vertebral venous system but did not propose the use of the vertebral venous system as a route of delivery of biologics to the brain. Byrod discussed a mechanism whereby substances applied epidurally can cross into the endoneurial space (Byrod G, Rydevik B, Johansson B R, Olmarker K. Transport of epidurally applied horseradish peroxidase to the endoneurial space of dorsal root ganglia: a light and electron microscopic study. J Peripher Nerv Syst, 5(4), 218-226 (2000)), but does not discuss the perispinal use of a biologic for delivery to the brain. Robinson (Robinson W H, Genovese M C, Moreland L W. Demyelinating and neurologic events reported in association with tumor necrosis factor alpha antagonism: by what mechanisms could tumor necrosis factor alpha antagonists improve rheumatoid arthritis but exacerbate multiple sclerosis? Arthritis Rheum, 44(9), 1977-1983 (2001)) states the prevailing view that systemic administration of etanercept does not lead to therapeutic concentrations of etanercept in the brain, because systemically administered etanercept does not cross the blood-brain barrier (BBB). Olmarker has filed applications regarding the use of anti-TNF molecules for treatment of spinal disorders, including US20010027175, 20010055594, 20030176332, 20050220791, 20010027199, and 20030039651, which have led to U.S. Pat. Nos. 6,635,250, 6,649,589, and 7,115,557 and others. None of these documents teaches perispinal administration of a biologic for delivery to the brain.
The in vivo distribution of radiolabeled etanercept delivered by perispinal etanercept in a mammal has been investigated. Perispinal administration resulted in more selective delivery of etanercept into the cerebrospinal fluid within the cerebral ventricles than did systemic (ventral tail vein) administration. See Tobinick E., Perispinal etanercept: a new therapeutic paradigm in neurology. Expert Rev Neurother, 10(6), 985-1002 (2010).
Methods
Animal studies were conducted in accordance with the applicable protocols by the Stanford Animal Care Committee. Etanercept (Immmunex, Amgen) was commercially purchased in powder form. Preparation of 64Cu-DOTA (1,4,7,10-tetraazadodecane-N,N′,N″,N′″-tetraacetic acid (DOTA)-etanercept was as previously described (Cao Q, Cai W, Li Z B et al. PET imaging of acute and chronic inflammation in living mice. Eur J Nucl Med Mol Imaging, 34(11), 1832-1842 (2007)). 150 microliters of 64Cu-DOTA-etanercept solution (ca. 1 mCi) was injected overlying the cervical spine of a 250 g Sprague-Dawley rat at the C 6-7 level using a 30 gauge needle at a depth of 6 mm while the rat was anesthetized with 2.5% isoflurane inhalation anesthesia. The rat was then placed in the head down position by tail suspension for three minutes, immediately followed by placement horizontally in the bed of a microPET imaging scanner (microPET R4 rodent model scanner, Siemens Medical Solutions USA, Inc.) designed for 5-min static scans; the scan was initiated two minutes after placement in the scanner bed and was performed from five to ten minutes after etanercept administration. The rationale for this method of peripheral administration is to deliver etanercept into the cerebrospinal venous system. The images were reconstructed by a 2-dimensional ordered-subsets expectation maximum (OSEM) algorithm, and no correction was necessary for attenuation or scatter correction.
Results
MicroPET imaging revealed accumulation of 64Cu-DOTA etanercept within the lateral and third cerebral ventricles within minutes of peripheral perispinal administration, with concentration within the choroid plexus and into the CSF suggested by the microPET images.
PET (Positron Emission Tomographic) image, transverse section, of a living rat brain following perispinal extrathecal administration of 64Cu-DOTA-etanercept, imaged 5 to 10 minutes following etanercept administration, gave a pattern consistent with penetration of 64Cu-DOTA-etanercept into the cerebrospinal fluid in the lateral and third ventricles. A horizontal linear enhancement within the lateral ventricles was noted, which is suggestive of accumulation of tracer within the choroid plexus.
The prior art fails to disclose or teach the use of perispinal administration without direct intrathecal or epidural injection of biologics, as a way of treating brain injury where said biologic is delivered via the vertebral venous system, and provides the patient with a better opportunity to heal, slows disease progression, improves brain function or otherwise improves the patient's health.